Harvesting Invasive Cattails

Restores Coastal Wetlands

Harvesting invasive cattails in 200 acres of coastal wetlands helped native plants return, restored habitat and paved the way for fish to flourish.

Description

The coastal wetlands surrounding the Straits of Mackinac, where Lakes Michigan and Huron meet, are some of the highest quality wetlands remaining in the Great Lakes region. Unfortunately, many of these marshes have become overrun by non-native cattails, a water reed. In addition to outcompeting native plants, invasive cattails and their dead stalks clog the wetlands, altering their natural flow and harming habitat. They also prevent Great Lakes fish, such as northern pike and yellow perch, from accessing their spawning grounds in the coastal wetlands. Thanks to a grant from the Great Lakes Restoration Initiative, researchers from Loyola University Chicago combined practical restoration of these wetlands with research into alternative approaches to cattail control. Their prior research demonstrated that commonly used controls such as fire and herbicide might effectively kill cattail stands, but did not remove the problematic dead stalks that block fish access. To address this, the researchers designed a new approach: using an aquatic tractor, workers harvested and removed invasive cattails from 200 acres of wetlands. In other areas, workers dug channels that allowed water to flow through the cattail stands, creating passageways for fish and other aquatic wildlife. The researchers also set up experimental plots to conduct variations on these treatment techniques. They are currently collecting and interpreting data from these experimental plots, and hope to understand which methods offer the most promise for future restoration success. The researchers are also investigating potential applications for the huge quantities of biomass they are harvesting, such as biofuel or compost.

Resource Challenges Addressed

  • Aquatic invasive plants
  • Lack of fish and wildlife habitat
  • Altered wetland water flow

NORTHERN MICHIGAN CATTAIL REMOVAL

Cattails by a shore

Invasive cattails, like the ones pictured above, dominated the shoreline near the Straits of Mackinac. After the removal of cattails, native shore plants have been able to return. Credit: Wikimedia.

Results and Accomplishments

Workers treated 200 acres of coastal wetlands to remove invasive cattail stands, restoring the natural flow of the wetlands, improving habitat, and allowing aquatic wildlife to access the wetlands from the open water. Removing the cattails also stimulates the germination of seed banks, allowing native plants to return to the marshes. Restoring plant diversity further enhances habitat quality. The experimental aspect of this project will give researchers and restoration managers a better understanding what technique produces the best results for coastal wetland restoration.